Process for testing catalysts using thernography

ABSTRACT

Apparatus for testing catalyst candidates including a multi-cell holder e.g. a honeycomb or plate, or a collection of individual support particles that have been treated with solutions/suspensions of catalyst ingredients to produce cells, spots or pellets holding each of a variety of combinations of the ingredients and dried, calcined or treated as necessary to stabilize the ingredients in the cells, spots or pellets. The apparatus also includes structure for contacting the catalyst candidates with a potentially reactive feed stream or batch e.g., biochemical, gas oil, hydrogen plus oxygen, propylene plus oxygen, CCl 2 F 2  and hydrogen, etc. The reaction occurring in each cell can be measured, e.g. by infrared thermography, spectroscopic detection of products or residual reactants, or by sampling, e.g. by multistreaming through low volume tubing, from the vicinity of each combination, followed by analysis e.g. spectral analysis, chromatography etc., or by observing temperature change in the vicinity of the catalyst e.g. by thermographic techniques, to determine the relative efficacy of the catalysts in each combination. Robotic techniques can be employed in producing the cells, spots, pellets, etc.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to the general field of catalysttesting, generally classified in U.S. Patent Class 502 or 252.

[0003] 2. Description of the Prior Art

[0004] Prior Art will include C & E News, 8 Jan. 1996, p.30 whichteaches reactive plastics, and the many catalyst testing devices andprocesses known to the petroleum refining art. F. M. Menger, A. V.Fliseev, and V. A. Migulin, “Phosphatase catalysts developed viacombinatorial organic chemistry”, J. Org. Chem. Vol. 60, pp 6666-6667,1995. Xiang, 268 Science 1738 and Bricenol, 270 Science 273, both oncombinatorial libraries of solid-state compounds; Sullivan, Today'sChem. At Work 14 on combinatorial technology; Nessler 59 J. Org. Chem.4723 on tagging of combinatorial libraries; Baldwin, 117 J. Amer. Chem.Soc. 5588 on combinatorial libraries.

II. Problems Presented by Prior Art

[0005] Catalyst testing is conventionally accomplished in bench scale orlarger pilot plants in which the feed is contacted with a catalyst underreaction conditions, generally with effluent products being sampled,often with samples being analyzed and results subjected to dataresolution techniques. Such procedures can take a day or more for asingle run on a single catalyst. While such techniques will have valuein fine-tuning the optimum matrices, pellet shape, etc., the presentinvention permits the scanning of dozens of catalysts in a singleset-up, often in less time than required for a single catalyst to beevaluated by conventional methods. Further, when practiced in itspreferred robotic embodiments, the invention can sharply reduce thelabor costs per catalyst screened.

SUMMARY OF THE INVENTION General Statement of the Invention

[0006] According to the invention, a multisample holder (support) e.g.,a honeycomb or plate, or a collection of individual support particles,is treated with solutions/suspensions of catalyst ingredients to fillwells in plates, or to produce cells, spots or pellets, holding each ofa variety of combinations of the ingredients, is dried, calcined orotherwise treated as necessary to stabilize the ingredients in thecells, spots or pellets, then is contacted with a potentially reactivefeed stream or batch e.g., to catalyze biochemical reactions catalyzedby proteins, cells, enzymes; gas oil, hydrogen plus oxygen, ethylene orother polymerizable monomer, propylene plus oxygen, or CCl2F2 andhydrogen. The reaction occurring in each cell is measured, e.g. byinfrared thermography, spectroscopic, electrochemical, photometric,thermal conductivity or other method of detection of products orresidual reactants, or by sampling, e.g. by multistreaming through lowvolume tubing, from the vicinity of each combination, followed byanalysis e.g. spectral analysis, chromatography etc, or by observingtemperature change in the vicinity of the catalyst e.g. by thermographictechniques, to determine the relative efficacy of the catalysts in eachcombination. Robotic techniques can be employed in producing the cells,spots. pellets) etc. Each of these parameters is discussed below:

[0007] Catalysts: Biotechnology catalysts include proteins, cells,enzymes, etc. Chemical conversion catalysts include most of the elementsof the Periodic Table which are solid at the reaction conditions.Hydrocarbon conversion catalysts include Bi, Sn, Sb, Ti, Zr, Pt, therare earths, and many possible candidates whose potential has not yetbeen recognized for the specific reaction. Many synergistic combinationswill be useful. Supported metals and metal complexes are preferred. Thechemical catalysts can be added to the substrate (support) as elements,as organic or inorganic compounds which decompose under the temperatureof the stabilizing step, depositing the element or its oxide onto thesubstrate, or as stable compounds.

[0008] Supports: Supports can be inert clays, zeolites, ceramics,carbon, plastics, e.g. reactive plastics, stable, nonreactive metals, orcombinations of the foregoing. Their shape can be porous honeycombpenetrated by channels, particles (pellets), or plates onto whichpatches (spots) of catalyst candidates are deposited or wells in plates.Conventional catalyst matrix materials such as zeolites e.g. zeoliteUSY, kaolin, alumina, etc. are particularly preferred as they cansimulate commercial catalysts.

[0009] Preparation: The catalyst candidate precursors can be depositedonto the supports by any convenient technique, preferably by pipette orabsorbing stamp (like a rubber stamp), or silk screen. In preferredembodiments, the deposition process will be under robotic control,similar to that used to load multicell plates in biochemical assays.Many of the spots of catalyst will be built up by several separatedepositions e.g. a channel penetrating a honeycomb can be plugged at onethird of its length and the channel filled with a catalyst solution inits upper third, then the plug can be moved to the two-thirds point inthe channel and a second catalyst pipetted in, then the plug can beremoved and a third catalyst solution added, resulting in a channel inwhich reactants contact three catalysts successively as they flowthrough the channel. Catalyst can also be added by ion exchange, soliddeposition, impregnation, or combination of these. The techniques ofcombinatorial chemical or biological preparation can preferably beutilized to prepare an array of candidate catalysts with the invention.Coprecipitates of two or more catalysts can be slurried, applied to thesupport, then activated as necessary. Catalysts can be silk screenedonto a support plate or inside of a support conduit, and successivescreenings can be used to add different catalyst combinations todifferent spots.

[0010] Stabilizing Step: Once the catalysts are in place on the support,any suitable technique known to the art can be used to stabilize, and/oractivate the particular catalysts chosen, so they will remain in placeduring the reaction step. Calcining, steaming, melting, drying,precipitation and reaction in place will be particularly preferred.

[0011] Reactants: The Invention has utility with any reaction which canbe enhanced by the presence of a catalyst, including biologicalreactions and inorganic and organic chemical reactions. Chemicalreactions include polymerization reactions, halogenation, oxidation,hydrolysis, esterification, reduction and any other conventionalreaction which can benefit from a catalyst. Hydrocarbon conversionreactions, as used in petroleum refining are an important use of theinvention and include reforming, fluid catalytic cracking,hydrogenation, hydrocracking, hydrotreating, hydrodesulfurizing,alkylation and gasoline sweetening.

[0012] Sensors: The sensors used to detect catalytic activity in thecandidate catalysts are not narrowly critical but will preferably be assimple as practical. Chromatographs, temperature sensors, andspectrometers will be particularly preferred, especially those adaptedto measure temperature and/or products near each specific catalyst spote.g. by multistreaming, multitasking, sampling, fiber optics, or lasertechniques. Thermography, as by an infrared camera recording thetemperature at a number of catalyst sites simultaneously, isparticularly preferred. Other suitable sensors include NMR, NIR, TNIR,electrochemical, fluorescence detectors, Raman, flame ionization,thermal conductivity, mass, viscosity and stimulated electron or X-rayemission Sensors can detect products in a gas or liquid stream or on thesurface of the support.

[0013] Endothermic reactions exhibit reduced temperature at bestcatalysts. Some sensors employ an added detection reagent, e.g. ozone toimpart chemiluminesce.

[0014] Taggants: Optionally taggants (labels) can be added to identifyparticular catalysts, particularly where particles are employed assupports for the catalysts. These taggants can be conventional asdiscussed in the literature. Taggants can be chemicals which are stableat reaction conditions or can be radioactive with distinctive emissions.The techniques of combinatorial chemistry will be applicable withtaggants as well as with catalysts chosen to suit the particularreaction to be enhanced by the catalyst.

[0015] Batch or Continuous: While the invention will be preferred on aflow basis, with reactants flowing by the catalyst spots under reactionconditions, batch testing e.g. in a stirred autoclave or agitatedcontainers, can be employed, particularly in biological reactions.

[0016] Temperatures, pressures, space velocities and other reactionconditions: These will be determined by the reactants and reaction.Elevated pressures can be provided as reaction conditions by encasingthe support in a reaction chamber with a sapphire or similar window forobservation by the sensing means, or with pressure-tight leads extendingthrough the reactor walls.

II. Utility of the Invention

[0017] The present invention is useful in the testing of catalysts forbiotechnology, for promotion of gas phase and liquid phase reactions;under batch or, preferably, continuous flowstream conditions; atelevated, reduced or atmospheric pressure; and saves both elapsed timeand labor in screening for improved catalysts to promote a desiredreaction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a schematic diagram of a preferred honeycomb supportwith a robotic pipetting device depositing different combinations ofcatalyst ingredients into each of the channels running through thehoneycomb, which is thereafter calcined to stabilize the catalysts ineach channel.

[0019]FIG. 2 is shows schematically the honeycomb of FIG. 1 beingcontacted by reactants flowing through the channels.

[0020]FIGS. 3a and 3 b are alternative schematic diagrams of one channelof the honeycomb of FIG. 2 with a detector sensing the products exitingthe channel by measuring absorption in a laser beam directed through theproducts or the channel.

[0021]FIG. 4a shows a channel plugged at its midpoint prior to receivinga solution of catalyst and

[0022]FIG. 4b shows the plug moved to the end of the channel, so as toform a channel having one catalyst in one half its length and anothercatalyst in its other half.

[0023]FIG. 5 shows schematically a sheet of support onto which 15 spotsof different catalyst combinations have been deposited, as discussed inexample 1.

[0024]FIG. 6a shows an array of particles (pellets) of support in placein a reactor after having been ion exchanged with different catalystcombinations on different pellets (denoted schematically by differentmarkings on the pellets in the Figure).

[0025]FIG. 6b shows a packed reactor which is less preferred becauseupstream pellets see fresh feed, while downstream pellets see partiallyreacted feed.

[0026]FIG. 7 shows schematically the use of various detectors on thecandidate catalyst array of FIG. 5.

[0027]FIG. 8 shows schematically the use of thermal, electrochemical,flame ionization, etc. detectors on the candidate catalyst array of FIG.5.

[0028]FIG. 9 shows schematically the use of low volume sampling tubeswith various analyzers on the candidate catalyst array of FIG. 5.

[0029]FIG. 10 shows schematically the use of a candidate catalyst arraydeposited on the interior of a monolith.

[0030]FIG. 11 shows schematically the use of a flow reactor withsapphire window open to various detectors on the candidate catalystarray of FIG. 5, and shows optional pressure tight electrical leads 13for leading to a detector.

[0031]FIG. 12 shows schematically the apparatus of Example 13.

[0032]FIG. 13 shows schematically the apparatus of Examples 14 and 16.

DESCRIPTION OF THE PREFERRED EMBODIMENT EXAMPLE 1

[0033] Referring to FIG. 1, a sheet of alpha alumina 10 is washcoatedwith particles of porous gamma-alumina by standard methods. Solutions ofoxalate salts of 12 different transition metal elements are prepared inthe wells of a 24 well microtiter dish made of polystyrene. A BeckmanBiomek 2000 robotic automated liquid handling system is used to preparedilutions and mixtures from the original stocks, again in the wells ofmicrotiter style plates. The robot is used to deposit 20 microtiteraliquots of each of the resulting solutions at defined positions (spots)12 on the surface of the alumina support 10, which is then dried,calcined and inserted into a reactor capable of temperature control attemperatures from 100 to 350 degrees centigrade. After reduction, apotentially reactive mixture of oxygen and hydrogen is fed to thereactor. An Agema infra-red sensitive camera 14 is used to observe thealumina support through infra-red-transparent sapphire windows 16 shownin FIG. 11, via a polished metal mirror. The camera is set so that thelower end of its dynamic range corresponds to a temperature of about 40degrees C. below the feed temperature and the maximum signal isassociated with a temperature about 200 degrees higher. Compositionscatalyzing the reaction are revealed by the localized temperatureincreases (decreases for endothernic reactions) around spots 12 of thatcomposition, as shown on photograph 18 in FIG. 5.

EXAMPLE 1a

[0034] Catalysts are alternatively identified by conducting the reactionin the presence of strong ultraviolet and/or visible light illumination.with infrared thermography being conducted immediately after theillumination is turned off, or through the use of a short pass filter onthe illumination source to eliminate contaminating infra-red radiation.

EXAMPLE 2

[0035] Referring to FIG. 2, a porous alumina monolith 20 (Corning)having square or circular cross-section channels extending in a regulararray through its entire thickness is treated in each channel with asolution of catalyst precursors of differing compositions, with eachcomposition being segregated in its own channel. After drying,calcination, etc., the activated monolith is placed in contact with aflowing potentially reactive mixture at an elevated temperature, andobserved in the infra-red using an Agema model camera. The enthalpy ofreaction produces localized temperature differences in the vicinity ofcompositions exhibiting catalytic activity and these are observed astemperature variations near the exits of the channels.

EXAMPLE 3

[0036] Referring to FIG. 3, a porous ceramic monolith 20 of the typedescribed in Example 2, bearing various catalyst compositions in itschannels is installed in a reactor (not shown) in such a way that theentire length of each channel can be observed through sapphire windowsat the ends of the reactor. A broad-spectrum thermal infrared source isinstalled at one end of the reactor, giving an areal infrared energyflux density. An Agema IR-sensitive camera is positioned in such a wayas to observe the infra-red source directly through a significantfraction of the pores. An interferometric or other filter is installedon one side of the reactor between the camera and the infra-red sourcesuch that the light reaching the camera from the source is substantiallylimited to wavelengths between 4 and 4.5 microns. Observation ofabsorbency at this wavelength range is used to compare candidatecatalyst compositions on the basis of their production of carbondioxide, an undesired side product of the intended reaction. Catalystcompositions chosen for low carbon dioxide formation (in combinationwith high overall conversion activity as measured by infra-redabsorbance of the desired product or by infrared thermography) are foundto have high selectivity for the desired product over the carbon dioxideside product.

EXAMPLE 4

[0037] A collection of catalyst precursor compositions is produced byautomated liquid handling device, and a catalyst support particle iscontacted with each composition. After further treatment to stabilizeand activate the catalyst precursors, catalyst pellets are arrayed on asurface, exposed to a potentially reactive environment and theiractivity determined by infrared thermography.

EXAMPLE 5

[0038] Solutions of combinations of catalyst precursors are prepared ina variety of separate vessels. Each composition also contains a smallquantity of a labeling material (e.g., stable isotopes of the elementcarbon or sulfur in varying ratios). Catalyst support particles arecontacted with catalyst precursor preparations, and activated. Pelletsare then contacted one at a time with a potentially reactive mixture(for example, by elutriation into an enclosed volume) and their activitymeasured (by thermography, by spectroscopic measurement of products, orsampling of the surrounding vapor or liquid phase). Particles showingactivity are collected and individually analyzed for their content ofthe labeling material so as to determine the composition giving thedesired catalytic activity.

EXAMPLE 6

[0039] Example 2 is repeated except that only a portion of the porelength is coated with a catalyst candidate so as to allow forobservation of unmodified monolith pore wall as a control referencestandard for optical uniformity.

EXAMPLE 7

[0040] The emissivity of the support monolith pores of the support 20 ofExample 2 is mapped at a wavelength of interest by holding the monolithat the intended experimental temperature in reactants. Digitally storedmaps of the emissivity are used to normalize the infra-red energy fluxmeasured under experimental conditions, to improve the accuracy withwhich local temperatures can be estimated.

EXAMPLE 8

[0041] A surface of high, substantially uniform emissivity is located atthe end of the monolith of Example 2, away from the camera, in closeradiative heat transfer/contact with the monolith channel material. Thetemperature of the portion of the surface closest to the open end ofeach channel is observed. In this case, it is necessary that gas beadmitted into the channels past the uniform radiative surface, either bymeans of pores or by means of a small offset between the radiativesurface and the monolith.

EXAMPLE 9

[0042] Alternatively, spots of catalysts can be deposited on the innersurface of a reactor e.g. a tube formed of the support material as shownin FIG. 10, and temperature of the corresponding spots on the outside ofthe reactor can be measured to determine by conduction whether therespective catalyst has increased or decreased in temperature under thereaction.

EXAMPLE 10

[0043] The process of Example 1 is repeated except that the reactantsare in the liquid phase and a liquid phase assay is used (FIG. 12) todetect the activity of individual catalyst candidates.

EXAMPLE 11

[0044] The experiment of Example 4 is repeated except that the metalloading is directly measured by dissolving the pellet and directlyanalyzing the metal loading.

EXAMPLE 12

[0045] A sheet of alpha alumina 5 in FIG. 12, is wash coated withparticles of porous gamma-alumina by standard methods. Solutions ofoxalate salts of 12 different transition metal elements are prepared inthe wells of a 24 well micro titer dish made of polystyrene. A BeckmanBiomek 2000 automated liquid handling system is used to preparedilutions and mixtures of the original stocks, again in the wells ofmicrotiter style plates. The Biomek robot 6 is used to deposit 40microliter aliquots of each of the resulting solutions at definedpositions on the surface of the alumina support, which is then dried,calcined and inserted into a reactor (as shown in FIG. 11) controlled ata temperature of 200 degrees centigrade. A gaseous mixture of hydrogen(97.5%) and oxygen (2.5%) is fed at a temperature of 200 degreescentigrade. Using the apparatus of FIG. 11, an infra-red sensitivecamera 14 is used to observe the alumina support throughinfra-red-transparent sapphire windows 16. The camera is set so that itslower range corresponds to the feed temperature and the maximum signalis associated with a temperature degrees 20 degrees higher. Compositionscatalyzing the reaction are revealed by the localized temperatureincreases around spots of that composition.

EXAMPLE 13

[0046] A porous alumina monolith 140 in FIG. 12, having square poresextending in a regular array through its entire thickness at a densityof 25 per square inch is washcoated with alumina particles. The channelsare then partially filled with solutions of differing compositions, eachcontaining one or more metal oxalate or nitrate salts, with eachcomposition being segregated in its own channel or set of channels.After drying and activation in the presence of hydrogen gas, theactivated monolith is placed into a sapphire-window-equipped reactor 150in which it can be observed in the infrared using an IR-sensitive camera145. The camera is positioned in such a way as to observe the walls ofthe support. The relative emissivity of the support at each pixel isdetermined by imaging the monolith in the IR while holding the reactorand monolith at each of several constant temperatures while flowingnitrogen gas 153 through the reactor.

[0047] The reactor is then fed with a gas mixture of 2.5 mole % oxygenin hydrogen 154. The reactor and feed temperatures are originally set to40 degrees centigrade, and are gradually increased While thecatalyst-bearing monolith is repeatedly imaged in the IR. Thetemperature in each cell may be judged by observing the cell at aposition adjacent to the end of the catalyst-precursor-coated section ofthe channel, or by normalizing the observed IR energy emission by theemissivity calculated from the images taken under nonreactiveconditions. The compositions in the cells showing the earliesttemperature increase above the reactor temperature are useful ashydrogen oxidation catalysts.

EXAMPLE 14

[0048] A porous alumina monolith 140 in FIG. 13 having square channelsin a regular array extending through its entire 10 centimeter thicknessat a density of 25 per square inch is washcoated with alumina particles.The channels are then partially filled with solutions of differingcompositions, each containing one or more metal salts and in some casesalso candidate modifiers such as barium, cesium or potassium compounds,each composition being segregated in its own channel or set of channels.

[0049] After drying and reduction in the presence of hydrogen gas, theactivated monolith is placed into a reactor in which it can be observedthrough a sapphire window 172 using an IR-sensitive camera 170.

[0050] This first window 172 is positioned 0.5 centimeter from thesurface of the monolith. The camera 170 is positioned in such a way asto look through the window 172, through the channels of the support andthrough a second sapphire window 174 toward a source of IR radiation164.

[0051] The reactor 168 is then fed with methane gas, mixed with oxygenand argon, in such a way that the gas 165 flows through the channels ofthe monolith toward the camera. An optical filter 162 which selectivelypasses IR radiation at 4.3 microns, a wavelength which is stronglyabsorbed by carbon dioxide, is inserted between the IR source and thecamera. The effective concentration of carbon dioxide in each channel isinferred from the IR intensity at 4.3 microns seen in that channel. Thereading at 4.3 microns for each pixel is divided by the reading takenthrough a filter selective for an IR wavelength which is near 4.3microns, but which is not absorbed strongly by carbon dioxide, methaneor water, to compensate for potential optical artifacts.

[0052] Compositions giving high concentrations of carbon dioxide afterlong exposures to operating conditions are useful in catalytic oxidationof methane.

EXAMPLE 15

[0053] Solutions of combinations of catalyst precursors are prepared ina variety of separate vessels. Each composition also contains a smallquantity of a labeling material (e.g., stable isotopes of the elementsulfur in varying ratios unique to each composition). Catalyst supportparticles are contacted with the preparations of catalyst precursorcompositions, and activated. Pellets are then contacted one at a timewith a potentially reactive mixture (for example, by elutriation into anenclosed volume) and their activity measured (by thermography, byspectroscopic measurement of products, or sampling of the surroundingvapor or liquid phase). Particles showing activity are collected andindividually analyzed for their content of the labeling material so asto determine the composition giving the desired catalytic activity.

EXAMPLE 16

[0054] A Teflon block monolith 140 in FIG. 13, having square channels ina regular array extending through its entire thickness at a density of 9per square inch is prepared in such a way that a shallow well exists atthe bottom of each channel. Each well is charged with a differentpolymer preparation bearing sulfonic acid groups on its surface, and aporous retaining mesh installed to keep the polymer samples in place.

[0055] The catalyst-charged monolith is placed into a reactor in whichit can be observed through a window 172, positioned 0.5 centimeter fromthe surface of the block. A camera 170 is positioned in such a way as tolook via through the sapphire window, through the channels of thesupport and through a second window 174, toward a source of polarizedlight 164. A polarizer 162 is installed between the block and thecamera.

[0056] A sucrose solution 166 is fed to the reactor in such a way as toflow through the channels of the block. The angle of rotation ofpolarized light in passing through the liquid in each channel ismeasured by rotating the polarizer to various angles, and observing thevariation in brightness of the light passing through each channel. Thecandidate catalysts found in channels giving the greatest change in theangle of rotation are useful as catalysts of sucrose hydrolysis.

EXAMPLE 17

[0057] Catalysts for photooxidation of hexane are identified byconducting the reaction in the apparatus of Example 16 in the presenceof strong ultraviolet and/or visible light illumination, with infra-redthermography being conducted immediately after the illumination isturned off, or through the use of a short pass filter on theillumination source to eliminate contaminating infrared radiation.

EXAMPLE 18

[0058] Samples of cyanogen bromide-activated cross linked agarose beadsare exposed to solutions of alcohol oxidase at varied pHs, saltconcentrations, and enzyme concentrations. After coupling of the enzyme,residual active groups are quenched with ethanolamine, the beads arewashed, and each sample placed in a separate well of a multiwell plate.The plate is exposed to a flowing air stream containing ethanol vaporand observed with an Amber infrared-sensitive camera.

[0059] The samples showing the greatest temperature increase areselected as highly active immobilized alcohol oxidase catalysts.

EXAMPLE 19

[0060] Samples of cyanogen bromide activated cross linked agarose beadsare exposed to solutions of anti-alcohol oxidase antibodies at variedpHs, salt concentrations, and antibody concentrations. After coupling ofthe enzyme, residual active groups are quenched with ethanolamine. Thebeads are washed, exposed to a solution of alcohol oxidase) washedagain, and each sample placed in a separate well of a multlwell plate.The plate is exposed to a flowing air stream containing ethanol vaporand observed with an Amber infrared-sensitive camera.

[0061] The samples showing the greatest temperature increase areselected as highly active immobilized alcohol oxidase catalysts.

EXAMPLE 20

[0062] A ceramic monolith having channels arranged in perpendicularrow/column format passing through its entire thickness is washcoatedwith porous alumina particles and all the channels in each column aretreated with the same catalyst precursors, which are activated. Apotentially-reactive stream is flowed through the channels of themonolith, and a multiwavelength beam of radiation is passed over thesurface of the monolith, parallel to each column, to a detector situatedat the end of the column. The composition of the stream leaving thepores in that column is estimated by processing the detector output,including Fourier transformation and/or weighted summation/differencingof the intensities at different wavelengths.

EXAMPLE 21

[0063] Pellets bearing catalytically-active groups capable of catalyzingthe conversion of both the D- and L-stereoisomers of a reactant aretreated with a variety of substances potentially capable ofpreferentially suppressing (temporarily or permanently) the conversionof the L-stereoisomer of that compound by that catalyst. The pellets aredistributed among the wells of a multiweli plate and exposed to amixture of the isomers of the compound to be modified. Pellets treatedwith the suppressor giving the greatest reduction in the activity forconversion of the L-isomer are useful in stereoselective modification ofthe D-isomer.

EXAMPLE 22

[0064] A ceramic monolith having channels arranged in perpendicularrow/column format passing through its entire thickness is washcoatedwith porous alumina particles and the channels treated with catalystprecursors, which are activated. A potentially-reactive stream is flowedthrough the channels of the monolith. A manifold consisting of an arrayof tubes, each smaller than the dimensions of an individual channel, isused to introduce a stream containing ozone into the stream flowingthrough each channel, near its outlet. Reaction of the introduced ozonewith the desired product liberates light, which is detected by a cameradirected at the monolith. The catalyst composition giving the strongestlight output is a useful catalyst for conversion of the reactants to theozone-reactive desired product.

EXAMPLE 23

[0065] A ceramic monolith having channels arranged in perpendicularrow/column format passing through its entire thickness is washcoatedwith porous alumina particles and the channels treated with catalystprecursors, which are activated and then exposed to a potentiallydeactivating substance. A potentially-reactive stream is flowed throughthe channels of the monolith. A manifold consisting of an array oftubes, each smaller than the dimensions of an individual channel 71 isused to sample the stream flowing within each channel. Samples from eachchannel in turn are introduced into a gas chromatograph-massspectrometer combination through an arrangement of switching valves, andcatalyst compositions giving the highest yield of desired products areuseful in conversion of that reactive stream.

Modifications

[0066] Specific compositions, methods, or embodiments discussed areintended to be only illustrative of the invention disclosed by thisspecification. Variations on these compositions, methods, or embodimentsare readily apparent to a person of skill in the art based upon theteachings of this specification and are therefore intended to beincluded as part of the inventions disclosed herein. For example,statistically-designed experiments, and automated, iterativeexperimental process methods can be employed to obtain furtherreductions in time for testing. Attachment/arraying of preformedcatalytic elements (especially precipitates, also single molecules andcomplexes such as metallocenes) onto a support, preferably byprecipitating or deposition is useful in many cases.

[0067] Detection can involve addition of some reagent to the streamleaving each candidate, the reagent allowing detection of a catalystproduct through staining or reaction to give a detectable product,light, etc.

[0068] The supports can comprise arrays with special arrangements fore.g., a header of multiple delivery tubes for uniform flow distribution,inserted into each channel in a block.

[0069] The detection means can comprise electrochemical means, or agamma camera for metals accumulation measurement, imaging elementalanalysis by neutron activation and imaging by film or storage plate ofemitted radioactivity, temperature measurement by acoustic pyrometry,bolometry, electrochemical detection, conductivity detection, liquidphase assay, preferably dissolving the support pellet and directlyanalyzing the metal loading; measuring refractive index in the liquidphase; observing the IR emissions of product gases directly, without theusual source and using instead the radiation hot gases emit atcharacteristic wavelengths.

[0070] Other modifications can include testing for selectivity afterdeliberately poisoning some sites, especially in chiral catalysis, etc.The formulations can be supported in the form of spots or layers on thesurface of a support containing wells or channels or channels extendingacross the entire extent of the support. The support can comprise a formof carbon, zeolite and/or plastic. The plastic can comprise a reactant.The support can hold a form of catalyst made by coprecipitation, oraluminum, or particles.

[0071] At least one of the formulations can preferably comprise amaterial selected from the group consisting of transition metals,platinum, iron, rhodium manganese, metallocenes, zinc, copper, potassiumchloride, calcium, zinc, molybdenum, silver, tungsten, cobalt andmixtures of the foregoing.

[0072] The label can comprise different isotopes or different mixturesof isotopes.

[0073] The reaction conditions can comprise a pressure greater than onebar absolute pressure and the contact can be at a temperature greaterthan 100 degrees centigrade

[0074] The method can comprise detection of temperature changes in thevicinity of a respective formulation due to reaction endotherm orexotherm.

[0075] The method can comprise treatment with a reducing agent. Thecontacting step can be carried out in the presence of compounds whichmodify the distribution of the metal within the porous support.

[0076] The candidate catalyst formulations can be contacted in the formof spots or layers on the surface of a support containing a washcoatsupported by an underlayer.

[0077] The stabilizing step can be carried out with a temperaturegradient or other means whereby certain candidate catalyst formulationsare exposed to different temperatures. The stabilizing can comprisecalcining, steaming, drying, reaction, ion exchange and/orprecipitation.

[0078] The detection of temperature changes due to reaction can employ acorrection for emissivity variations associated with differences inchemical composition.

[0079] The array of formulations to be tested can-comprise preformedmetallocenes or other catalytic complexes fixed to a support.

[0080] The infrared radiation can be detected through the use ofnondispersive infrared spectroscopy, or infrared-sensitive photographicfilm. The detector means can comprise means for physically scanning overan array of candidate formulations.

[0081] Observations at multiple wavelengths can be processed bymathematical manipulation e.g. transformation, weighted summation and/orsubtraction, etc.

[0082] Reaction activity, reactants, or products can be detected throughthe use of an added reaction which signals the presence of reaction orparticular compounds or classes of compounds.

[0083] Chemiluminescence can be used as an indicator of reactionactivity, or particular compounds or classes of compounds.

[0084] A substantially collimated radiation source can be employed inproduct detection/imaging.

[0085] Multi-tube sampling can be used to lead into a mass spectrometer,chromatograph, or optical monitor.

[0086] To simulate aging, etc., the formulations can exposed to adeleterious agent which reduces the activity of at least one formulationby at least 10%, and then optionally exposed to steam, heat, H2, air,liquid water or other different substance(s) or condition(s) whichincrease the activity of at least one member of the collection by atleast 10% over its previously-reduced activity whereby regenerability,reactivatability, decoking, or other catalyst property is measured. Thedeleterious agent can comprise elevated temperature, V, Pb, Ni, As, Sb,Sn, Hg, Fe, S or other metals, H2S, chlorine, oxygen, Cl, and/or carbonmonoxide.

[0087] Reference to documents made in the specification is intended toresult in such patents or literature being expressly incorporated hereinby reference.

What is claimed is:
 1. (new) A method for evaluating a plurality ofcandidate catalysts, the method comprising providing a plurality ofcandidate catalysts having differing compositions in a parallel reactor,the reactor comprising one or more temperature sensors in thermalcommunication with each of the plurality of candidate catalysts,simultaneously contacting the plurality of candidate catalysts with oneor more reactants under reaction conditions to catalyze at least onereaction with each of the plurality of candidate catalysts, detectingtemperature changes due to the heat of reaction of the catalyzedreactions using the temperature sensors, and determining the relativeefficacy of the plurality of candidate catalysts based on the detectedtemperature changes.
 2. (new) The method of claim 1 wherein theplurality of candidate catalysts are provided at a plurality of sites ona common support.
 3. (new) The method of claim 1 wherein each of theplurality of candidate catalysts are tagged or labeled to identifyparticular catalyst candidates, the method farther comprising collectingcandidate catalysts showing catalytic activity, and analyzing the tag orlabel of the collected candidate catalysts to determine the catalystcandidates having catalytic activity.
 4. (new) The method of claim 2wherein the support is a plate or sheet having a surface comprising thecandidate-catalyst-containing sites.
 5. (new) The method of claim 2wherein the support is a plate having a plurality of wells ascandidate-catalyst-containing sites.
 6. (new) The method of claim 2wherein the support is a monolithic support comprising a plurality ofreaction channels as candidate-catalyst-containing sites.
 7. (new) Themethod of claim 2 wherein each of the plurality of candidate catalystsis in its own site on the support.
 8. (new) The method of claim 2wherein the temperature sensors are located in the vicinity of thecandidate catalysts.
 9. (new) The method of claim 1 wherein theplurality of catalyst candidates are chemical conversion catalysts. 10.(new) The method of claim 1 wherein the plurality of catalyst candidatesare hydrocarbon conversion catalysts.
 11. (new) The method of claim 1wherein the plurality of catalyst candidates are inorganic catalysts.12. (new) The method of claim 1 wherein the plurality of catalystcandidates are metals or metal oxides.
 13. (new) The method of claim 1wherein the plurality of catalyst candidates are transition metals ortransition metal oxides.
 14. (new) The method of claim 1 wherein theplurality of catalyst candidates are zeolites.
 15. (new) The method ofclaim 1 wherein the plurality of catalyst candidates are metallocenes.16. (new) The method of claim 1 wherein the plurality of catalystcandidates are enzymes.
 17. (new) The method of claim 1 wherein theplurality of catalyst candidates are cells.
 18. (new) The method ofclaim 1 wherein the plurality of catalyst candidates are supportedcatalysts.
 19. (new) The method of claim 1 wherein the plurality ofcandidate catalysts are simultaneously contacted with the one or morereactants in a plurality of reactor channels formed in a monolithicsupport.
 20. (new) The method of claim 1 wherein the one or morereactants are in the gas phase.
 21. (new) The method of claim 1 whereinthe one or more reactants are in the liquid phase.
 22. (new) The methodof claim 1 wherein the plurality of candidate catalysts comprisesfifteen candidate catalysts.
 23. (new) The method of claim 1 wherein theplurality of candidate catalysts comprises twenty-four candidatecatalysts.
 24. (new) The method of claim 1 wherein the plurality ofcandidate catalysts are contacted with the one or more reactants underreaction conditions that include a temperature greater than 100° C., andadditionally, or alternatively, a pressure of greater than 1 bar. 25.(new) The method of claim 1 wherein the plurality of candidate catalystsare formed by calcining catalyst precursors at different temperatures.26. (new) The method of claim 1 wherein the plurality of candidatecatalysts are provided at a plurality of sites on a common support, eachof the plurality of candidate catalysts being in its own site on thesupport.
 27. (new) The method of claim 1 wherein the plurality ofcandidate catalysts are simultaneously contacted with the one or morereactants in parallel reactor comprising a plurality of reactionchannels, each of the plurality of candidate catalysts being in its ownreaction channel.
 28. (new) The method of claim 27 wherein the parallelreactor comprises a plurality of reaction channels in a monolithicsupport.
 29. (new) The method of claim 27 wherein the parallel reactoris a flow reactor and the one or more reactants flow through each of theplurality of reaction channels.
 30. (new) The method of claim 27 whereinthe parallel reactor is a batch reactor pressurized with the one or morereactants.
 31. (new) A method for evaluating a plurality of candidatecatalysts, the method comprising flowing a reactant-containing streamthrough each of a plurality of reaction channels in a parallel flowreactor, each of the plurality of reaction channels comprising an inletfor receiving a reactant-containing stream, an outlet for discharging aproduct-containing stream, a catalyst-candidate, and one or moretemperature sensors in thermal communication with the catalystcandidate, the plurality of candidate catalysts having differentcompositions as compared between the plurality of reaction channels,simultaneously contacting the plurality of candidate catalysts with oneor more reactants under reaction conditions to catalyze at least onereaction in each of the plurality of reaction channels, detectingtemperature changes due to the heat of reaction of the catalyzedreactions using the temperature sensors, and determining the relativeefficacy of the plurality of candidate catalysts based on the detectedtemperature changes.
 32. (new) A method for evaluating a plurality ofcandidate catalysts, the method comprising providing a plurality ofcandidate catalysts having differing compositions at a plurality ofsites on a common support, simultaneously contacting the plurality ofcandidate catalysts with one or more reactants in a parallel reactorunder reaction conditions to catalyze at least one reaction with each ofthe plurality of candidate catalysts, the reactor comprising one or moretemperature sensors in thermal communication with each of the pluralityof candidate catalysts, detecting temperature changes due to the heat ofreaction of the catalyzed reactions using the temperature sensors, anddetermining the relative efficacy of the plurality of candidatecatalysts based on the detected temperature changes.